Shoe assembly with non-linear viscous liquid

ABSTRACT

Shoes and shoe sole assemblies and associated methods of manufacture are disclosed herein. One aspect of the invention is directed toward a shoe and shoe sole assembly made of a non-linearly viscous, SEBS block copolymer-based material that becomes more resilient as more energy is applied. The shoe and shoe sole assembly is configured with a heel and forefoot insert configured to fit within a recess in a midsole. In other embodiments, the non-linearly viscous, SEBS block copolymer-based material is mixed with at least one other polymer in a foam. The midsole is formed with a heel impact region and a forefoot region made of the foam.

TECHNICAL FIELD

Embodiments of the present disclosure relate to shoes and shoeassemblies with non-linear viscous liquid components.

BACKGROUND

Shoes of all types are subject to great amounts of stress throughrepeated, cyclical loading caused by walking, running, and otheractivities. Athletic shoes generally experience even more acute stressdue to the higher impact levels associated with athletic activities. Therepeated impact of a high-intensity gait causes great wear and evenbreak-down of many shoes. In addition, the impact is stressful to thewearer's body. Without proper support and cushioning, the foot, ankle,calf, knee, and even hip joints are challenged physically by athleticactivity. Proper alignment of joints, bones, and muscles of the foot,leg, and hip is crucial. A shoe that is improperly constructed, worndown, or improperly calibrated to the activity can cause off-axisloading of joints and bones. Off-axis loading can cause fatigue andtension to the wearer.

There have been many attempts to create a shoe sole that provides adurable, long lasting, and reliable support to the wearer throughouteven the most vigorous athletic activity. Many conventional materialsgenerally sacrifice responsiveness for comfort, or comfort forresponsiveness. Also, most materials are best suited either forstressful, high-impact activity such as running, or toward lower-levelactivities such as standing or walking. Many of previous attempts placea bladder or insert in the sole containing air, gel, plastic, or othermaterial to absorb energy from impact. These materials generally cannotprovide a range of response characteristics to different levels ofpressure and impact. In other words, a softer soled shoe that may bewell suited for standing and walking is not properly calibrated forhigher-impact levels. Similarly, a stiffer shoe that may provide properresiliency and performance for running or other high-energy activitiesis generally not well suited—even uncomfortable or painful—for lowerlevel activities.

Some attempts have been made to provide a shoe with dilatant (i.e.,shear-thickening) materials in the sole. These materials increase inviscosity as a function of the rate of shear (e.g., silly putty).Dilatant materials, however, are generally not accurately calibrated tothe responsiveness required for multiple levels of activity to provideoptimal responsiveness and comfort. Also, dilatant materials cannot bereadily injection molded or compression molded, increasing thecomplexity and cost of manufacture. There is a need for a shoe assemblythat can meet the needs of both high- and low-intensity activitieswithout sacrificing comfort or performance.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric illustration of an impact pattern of a footstepduring an average gait.

FIG. 2 is an illustration of a pair of shoes according to the presentdisclosure.

FIG. 3 is a top view of a left and right heel and forefoot shoe assemblyinserts in accordance with several embodiments of the presentdisclosure.

FIG. 4A is a cross-sectional side view of a heel insert in accordancewith several embodiments of the present disclosure.

FIG. 4B is a cross-sectional side view of a forefoot insert inaccordance with several embodiments of the present disclosure.

FIG. 5A is a cross-sectional rear view of a midsole and heel insert inaccordance with several embodiments of the present disclosure.

FIG. 5B is a cross-sectional rear view of a midsole and heel insert inaccordance with several embodiments of the present disclosure.

DETAILED DESCRIPTION

Aspects of the present disclosure are directed generally toward shoesand shoe assemblies and associated methods of manufacture, includingshoe components made of non-linearly viscous materials. One aspect ofthe present disclosure is directed toward a shoe sole assemblycomprising an insert, such as a heel insert made of a non-linearlyviscous, SEBS block copolymer-based material. The heel insert of oneembodiment has a generally curved teardrop shape with a generallycircular heel portion, and a tapered protrusion extending forward fromthe heel portion. The shoe assembly can also includes a forefoot insertsimilarly made of a non-linearly viscous, SEBS block copolymer-basedmaterial. The forefoot insert of one embodiment is a contoured insertthat comprises a generally oval-shaped portion positioned under aninside metatarsal of a foot, and an arcing protrusion extendinglaterally outwardly from the oval-shaped portion. The forefoot extensionis configured in an arcing shape to substantially underlie themetatarsals of the wearer's foot. A midsole is configured to receive theheel insert and the forefoot insert.

Other aspects of the present disclosure are directed to a shoe sole witha midsole portion having a heel impact region, and a forefoot impactregion. At least one of the heel impact region and the forefoot impactregion is formed of a non-linearly viscous, SEBS block copolymer-basedmaterial blended into a foam with at least one other polymer.

Other aspects of the present disclosure are directed to methods ofmanufacturing a shoe sole assembly, including forming a midsole with atleast one recess configured to receive at least one insert, and moldingat least one insert from a non-linearly viscous, SEBS blockcopolymer-based material to fit within the at least one recess. A topsurface of the insert and the midsole form an insole configured toreceive a foot. In some embodiments, the insole and/or sockliner canalso be made of a non-linearly viscous material, and can be made withthe same manufacturing techniques disclosed herein.

Still other aspects of the present disclosure are directed to methods ofmanufacturing a shoe sole. The methods include mixing a non-linearlyviscous, SEBS block copolymer-based material with at least one otherpolymer to create a foam, and molding the foam into a shoe sole with aheel impact region and a forefoot impact region. The methods alsoinclude forming a midsole to receive the heel impact region and theforefoot impact region, wherein the midsole, the heel impact region, andthe forefoot impact region comprise an insole surface configured toreceive a foot.

Various embodiments of the disclosure will now be described. Thefollowing description provides specific details for a thoroughunderstanding and enabling description of these embodiments. One skilledin the art will understand, however, that the disclosure may bepracticed without many of these details. Additionally, some well-knownstructures or functions may not be shown or described in detail, so asto avoid unnecessarily obscuring the relevant description of the variousembodiments.

The terminology used in the description presented below is intended tobe interpreted in its broadest reasonable manner, even though it isbeing used in conjunction with a detailed description of certainspecific embodiments of the disclosure. Certain terms may even beemphasized below; however, any terminology intended to be interpreted inany restricted manner will be overtly and specifically defined as suchin this Detailed Description section.

References throughout the specification to “one embodiment” or “anembodiment” means that a particular feature, structure, orcharacteristic described in connection with the embodiment and includedin at least one embodiment of the present disclosure. Thus, theappearances of the phrase “in one embodiment” or “in an embodiment” invarious places throughout the specification are not necessarily allreferring to the same embodiment. Furthermore, the particular features,structures, or characteristics may be combined in any suitable manner inone or more embodiments.

FIG. 1 illustrates a traditional foot impact pattern during a footstepof a normal gait cycle. The darkest portions 10 and 12 correspond to thearea between the first and second metatarsal, and the heel,respectively. Understandably, these are the areas of high impact duringa normal gait cycle. Lighter regions 14 and 16 show areas of slightlylesser impact surrounding the heel and under the third, fourth, andfifth metatarsal. The impact pattern follows generally the arcingpattern of the metatarsal heads, or the balls of the foot. Other impactareas are the toe areas 18 and a region 20 forward of the heel andtoward the outer edge of the foot print. The pattern of these impactregions illustrates the need for impact absorption or energy return atthese crucial areas. FIG. 1 depicts a traditional, average impactpattern. Throughout this disclosure, reference is made to an impactpattern; however, it is to be appreciated that different activities willcause higher or lower impact, and/or impact in different patterns thanthat shown in FIG. 1. The features of the present disclosure can beapplied to shoes for use with different activities by different users,wherein the associated impact pattern is different without departingfrom the scope of this disclosure.

FIGS. 2-5B illustrate various features of a shoe assembly in accordancewith various embodiments of the disclosure. FIG. 2 is an illustration ofa pair of running shoes 100 in accordance with the present disclosure.The shoes contain an upper 102 and a sole 104. The sole contains a heelinsert 106 and a forefoot insert 108. The heel insert 106 and forefootinsert 108 are positioned beneath the heel and forefoot, respectively,of the wearer of the shoes 100. The inserts 106 and 108 are generallyconfigured to match impact regions of a human foot. Generally, the areasof highest impact during a gait cycle are under heel and under the firstand second metatarsal heads of the forefoot. The inserts 106 and 108have a thickness generally corresponding to the level of typical orpotential impact loads at these regions, whereby portions of the insertsportions under the areas typically subjected to the highest loads arethicker than the portions under the portions of the foot typicallysubjected to lower loads. The inserts 106 and 108 will be described inmore detail below. It is to be appreciated that the shoes 100 depictedhere are for illustration purposes only, and that the present disclosureapplies to shoes of all types.

FIG. 3 is a top view of left and right shoe inserts 110 according to thepresent disclosure. While at times the present disclosure discusses aleft or right shoe/foot, it is to be appreciated that the left and rightshoe assembly features may or may not be mirrored in the right shoeassembly. According to selected embodiments of the present disclosure,the left heel insert 112 comprises a generally circular region 114positioned under the heel of the wearer. A tapered protrusion 116extends forwardly from the circular region 114. The shape of the heelinsert 112 generally corresponds to the impact regions experienced by ahuman foot during a normal gait cycle. As is shown in FIG. 3, thetapered protrusion 116 generally follows the outer portion of the footnear the heel between the heel and forefoot. The tapered protrusion 116terminates with a rounded tip 118.

The heel insert 112 comprises a plurality of channel recesses 120 andpin recesses 122. The shape, depth, configuration, and layout of theserecesses 120 and 122 can vary according to design preferences. Therecesses 120 and 122 generally provide greater flexibility and reducethe weight of the insert 112. Some of the recesses 120 and 122 canextend upward from the bottom of the insert 112 and some downward fromthe top of the insert 112, or all can extend from the top or the bottom.In some embodiments, the recesses 120 and 122 are generally configuredto match impact patterns from the foot. In this example, the recesses124 are positioned in a circular pattern around the generally circularregion 114. In some embodiments, the recesses 120 and 122 can comprisesealed cavities in the insert 112 to prevent adhesive and othermaterials from filling or contaminating the recesses 120 and 122.

The forefoot insert 130 comprises a generally oval-shaped portion 132,and an arcing protrusion 134 that extends in an arc from the oval-shapedportion 132. The shape of the arc can generally match the shape ofmetatarsal heads of the human foot, such that the forefoot insert 130provides maximum support to the areas of highest impact on the forefoot.The oval-shaped portion 132 is angled slightly, with the front portion136 inward of the rear portion 138. The forefoot insert 130 can containchannel recesses 120 and pin recesses 122 similar to those in the heelinsert 112.

FIG. 4A is a cross-sectional side elevation view of the heel insert 112in accordance with several embodiments of the present disclosure. Theheel insert 112 comprises a convex protrusion 142 extending downwardlyfrom the insert 112, and a top surface 143 that is generally flat. Thethickness and shape of the convex protrusion 142 can vary depending onthe intended application range of the shoe, and depending on thematerial of the inserts 112 and 130. FIG. 4B is a cross-sectional sideview of the forefoot insert 130 according to several embodiments of thepresent disclosure. In this embodiment, the forefoot insert 130 also hasa convex protrusion 144. In comparison to the convex protrusion 142 ofthe heel insert 112 in FIG. 4A, the protrusion 144 of the forefootinsert 130 is smaller. In other embodiments in which the inserts areconfigured for a different use involving more impact at the forefootthan at the heel, the forefoot insert 130 may be thicker and have a morepronounced dome-shaped profile 144. For example, activities such ascycling and dancing may involve more impact on the forefoot and lessimpact on the heel. For such activities, the forefoot insert 130 can bethicker than the heel insert 112. The heel insert 112 and the forefootinsert 130 are positioned in the sole assembly at locations andorientations that substantially correspond to the high impact regions ofthe human foot during a normal gait cycle, thereby absorbing the impactforces and other loads transferred to the wearer's bones, muscles, andjoints during the gait. Accordingly, off-axis joint and skeletal loadingto the wearer is significantly reduced, particularly during strenuous,high impact activities, such as running and other athletic activities.

In other embodiments of the present disclosure, the inserts can extendacross substantially the entire insole of the shoe. In these embodimentsthe inserts can have a thicker region at the heel and the forefoot insubstantially the same pattern as that depicted in FIG. 3. Otherembodiments can include heel and forefoot inserts substantially shapedand configured in FIG. 3 with the heel and forefoot inserts connected bya thin connection piece for ease of manufacture, transport, andassembly. It is to be appreciated that the inserts shown in FIG. 3 arean example of an impact pattern of a footstep during an activity such asrunning or walking. It is also to be appreciated that inserts accordingto the present disclosure that are intended for different uses withdifferent impact patterns can be shaped according to the impact patternof the activity. For example, driving an automobile may place pressureat the rear of the heel as the driver operates the pedals and theclutch—an impact pattern not experienced during a normal walking gait.Inserts accommodating this type of irregular impact pattern are withinthe scope of the present disclosure.

FIG. 5A is a cross-sectional rear view of a shoe assembly 150 inaccordance with the present disclosure. A midsole 152 is configured toreceive a heel insert 112 in a recess of the midsole 152. Although aheel insert 112 is shown in FIG. 5A, similar features can be applied toinserts of other types including forefoot inserts. In some embodiments,the midsole 152 comprises lips 154 that extend over a portion of theinsert 112 to hold the insert 112 in place. Other locking engagementswith other shapes and configurations can be positioned elsewhere in themidsole 152. The insert 112 can include a mating element such as ashoulder 156 configured to receive the lips 154 (or other lockingengagement). An adhesive can be used to reinforce the attachment betweenthe midsole 152 and the insert 112. In some embodiments, the shoulder156 can extend from the insert 112 a uniform distance around theperimeter of the insert 112. In other embodiments the dimensions of theshoulder 156 (and corresponding lips 154) can vary around the perimeterof the insert 112. For example, the shoulder 156 can be larger orsmaller at the sides than it is at the front and rear edges. Or theshoulder 156 can be larger or smaller at the inside and front than it isat the outside and rear. The various shoulder dimensions can improve theadhesion of the lips 154 and the shoulder 156 with or without anadhesive. The stress at different regions may be different depending onhow the shoe assembly 150 is used. Accordingly, the shoulder 156 andlips 154 can be sized to resist these stresses so that the insert 112 issecurely held in the midsole 152.

Midsole perimeter portions 159 extend generally around the perimeter ofthe midsole 152 and are configured to receive the foot of a wearer andto improve comfort and arch support. The top of the insert 112 isgenerally flat and in some embodiments is substantially flush with thesurface of the midsole 152. In other embodiments, an insole layer (notshown) is placed over the midsole 152 and the insert 112. The recess inthe midsole 152 is shaped such that the insert 112 fits within themidsole 152. Although the midsole 152 is shown here with a generallyconcave surface to receive the convex protrusion 142 of the insert 112,it will be appreciated that different embodiments can have differentconfigurations, including a concave surface with a larger or smallerradius than that depicted here, or with a flat or convex shape. Forexample, FIG. 5B is a cross-sectional view of a forefoot insert 130 anda midsole 152 in accordance with the present disclosure in which themidsole 152 has a cross-sectional shape 160 that mates with a similar,negative shape on the bottom of the insert 112. The forefoot insert 130is received within a similar recess in another portion of the midsole152. As discussed above, the forefoot insert 130 can have various shapesand sizes depending on the intended application or style.

The inserts 112 and 130 described above are constructed of anon-linearly viscous material, such as product numbers LC 331-178 or LC331-138 manufactured by GLS Corporation. These materials are SEBS(Styrene-ethylene-butadiene-styrene) block copolymer based materials.The material's resiliency is a function of a level of impact to thematerial. This material allows an athletic shoe, for example, to feelsoft and absorb energy while walking, but when the wearer begins to runor otherwise impact the material the shoe stiffens and provides desiredenergy return to the wearer's gait. The material will continue torespond to increased impact levels as the runner speeds up. Theresiliency is a function of speed and force of the steps of the wearer,and of the weight of the wearer. A heavier runner at one speed may causea higher level of resilience in the material than a lighter runner atthe same speed.

The inserts are durable and flexible. They resiliently return to theirunloaded shape when the impact is removed between footsteps. During anormal gait cycle the heel and forefoot inserts are loaded differently.The primary force on the heel insert is the downward force from the heelwhich compacts the insert, while a significant force is applied to theforefoot insert when it is flexed as the wearer pushes off from theground. Both inserts return this energy to the gait when the impact ishigh by springing the wearer's heel back upward or propelling the wearerforward. When the impact is low, the inserts revert back to theirsofter, more energy-absorbing state where the energy return iscorrespondingly (and appropriately) less. The higher the impact of thegait, the more energy is returned to the gait. The result is a shoe thatis comfortable to wear for walking without sacrificing higher-endperformance for running or training.

Absorbing energy and returning energy according to impact energyprovides several advantages. The wearer experiences both comfort andperformance without sacrificing either. The energy return and absorptionprovides greater stability to the wearer during the gait by reducingoff-axis loading. There is less stress to joints in the foot, knee, andhip because the moments placed on the foot are lessened by the reductionof off-axis loading. Because of the material, the shoes providecushioning support at the right times and in the right places. The feelof the shoe is tuned to individual runners and walkers because theresiliency of the material factors in weight and activity and respondsappropriately to each.

In addition to the energy-return advantages provided by the material'sresiliency, the material and configurations of the present disclosurecan be positioned and configured to provide stability to a wearer'sgait. Excessive off-axis loading can be caused by pronation of thewearer's foot. The footwear can be designed to include the non-linearviscous material in the form of inserts or other structural componentsincluding formed integrally within a midsole substantially as discussedabove, in selected positions to counteract pronation or supination toprovide stability to the wearer's gait. Similar to the action describedabove, the material's increased stiffness and resiliency athigher-impact levels will increase the stability protection provided bythe shoes. Thus, a runner who pronates (or supinates) slightly whilewalking but more heavily while running or jumping causes the material torespond to the higher impact levels and counteract the heavier pronation(or supination).

One additional advantage of this material is that, unlike dilatantmaterials, it can be made into the various shapes through injectionmolding or compression molding. These are well-known and cost-effectivemethods of manufacture, so shoes made by these methods are lessexpensive to manufacture. The midsole 152 and other components of theshoe assembly can be constructed from an alpha olephin polymer blend, apolyolefin polymer blend, or from a polymer alloy with polyolefins.These materials can also be injection molded or compression molded intoshape.

The above embodiments include a midsole and an insert made of disparatematerials. In other embodiments the SEBS material can be incorporatedinto a foam with at least one other material, such as at least one ofthe materials used in previous embodiments for the midsole, or anotherpolymer material. The materials can be mixed together into a foam whichcan be injection molded or compression molded into shape. In someembodiments the foam is limited to the heel and forefoot region insubstantially the same regions covered by the inserts of FIGS. 4A, 4B,5A, and 5B. In other embodiments the SEBS material is more heavilyconcentrated in the high impact regions and may be distributed as afunction of impact level of an average gait (which may vary depending onthe activity) but is not limited to those regions. In still otherembodiments the SEBS material can be distributed in an even or otherselected distribution pattern throughout the foam and thereforethroughout the sole of the shoe.

The above-detailed embodiments of the disclosure are not intended to beexhaustive or to limit the disclosure to the precise form disclosedabove. Specific embodiments of, and examples for, the disclosure aredescribed above for illustrative purposes, but those skilled in therelevant art will recognize that various equivalent modifications arepossible within the scope of the disclosure. For example, whereas stepsare presented in a given order, alternative embodiments may performsteps in a different order. The various aspects of embodiments describedherein can be combined and/or eliminated to provide further embodiments.Although advantages associated with certain embodiments of thedisclosure have been described in the context of those embodiments,other embodiments may also exhibit such advantages. Additionally, notall embodiments need necessarily exhibit such advantages to fall withinthe scope of the disclosure.

Unless the context clearly requires otherwise, throughout thedescription and the claims, the words “comprise,” “comprising,” and thelike are to be construed in an inclusive sense as opposed to anexclusive or exhaustive sense, i.e., in a sense of “including, but notlimited to.” Additionally, the words “herein,” “above,” “below,” andwords of similar import, when used in this application, shall refer tothis application as a whole and not to any particular portions of thisapplication. Use of the word “or” in reference to a list of items isintended to cover a) any of the items in the list, b) all of the itemsin the list, and c) any combination of the items in the list.

In general, the terms used in the following claims should not beconstrued to limit the invention to the specific embodiments disclosedin the specification unless the above-detailed description explicitlydefines such terms. In addition, the inventors contemplate variousaspects of the disclosure in any number of claim forms. Accordingly, theinventors reserve the right to add claims after filing the applicationto pursue such additional claim forms for other aspects of thedisclosure.

1. A shoe sole assembly comprising: a heel insert made of a non-linearly viscous, SEBS block copolymer-based material, the heel insert comprising: a generally circular heel portion; and a tapered protrusion extending forward from the heel portion; a forefoot insert made of a non-linearly viscous, SEBS block copolymer-based material, the forefoot insert comprising: a generally oval-shaped portion positioned under an inside metatarsal of a foot; and an arcing protrusion extending laterally outwardly from the oval-shaped portion, wherein the forefoot extension is configured in an arcing pattern of metatarsals of a foot to substantially underlie the metatarsals; and a midsole configured to receive the heel insert and the forefoot insert.
 2. The shoe sole assembly of claim 1 wherein a top surface of the heel portion is generally flat, and a bottom surface is generally dome-shaped
 3. The shoe sole assembly of claim 1 wherein the tapered protrusion tapers in at least one of a width direction and a thickness direction.
 4. The shoe sole assembly of claim 1 wherein the oval-shaped portion is slightly thicker than the arcing protrusion.
 5. The shoe sole assembly of claim 1 wherein the non-linearly viscous, SEBS block copolymer-based material is at least one of an injection molded material or a compression molded material.
 6. The shoe sole assembly of claim 1 wherein the non-linearly viscous, SEBS block copolymer-based material is at least one of thixotropic, rheopectic, and pseudo-plastic.
 7. The shoe sole assembly of claim 1 wherein the heel insert and the forefoot insert are configured to fit within recesses in the midsole.
 8. The shoe sole assembly of claim 1 wherein at least one of the heel insert and the forefoot insert has a plurality of recesses configured to increase flexibility and decrease weight of the at least one insert.
 9. The shoe assembly of claim 1 wherein the material has a first resiliency in response to a first impact and a second resiliency in response to a second impact.
 10. The shoe assembly of claim 1 wherein the heel insert has a first resiliency and the forefoot insert has a second resiliency. 